In a large dutch oven or stock pot, saute the sausage and onions in olive oil over medium-high heat for about 8 minutes. The sausage should be cooked through, and the onions should be golden brown.
Add the garlic and saute for another 2 minutes. Stir frequently - you don't want the garlic to burn.
Add the chicken broth, tomato paste, tomatoes and their juice, dried basil and oregano, bay leaves, salt and pepper, cayenne (if you're using it) and the lasagna noodles. Bring to a boil. Continue boiling for about 15 minutes, or until the noodles are tender.
At this point, you might want to add 1 to 2 cups more chicken stock (you could add water instead), depending on how thin you like your soup.
Add the salt and pepper, and adjust seasonings as you like them. Remove the bay leaves.
Ladle soup into bowls and top with mozzarella and parmesan cheeses. Serve immediately.
Soup (without the cheese added) will keep for about a week in the fridge and for up to six months in the freezer.